N-(1-bicyclic aryl-propyl-2)-n&#39;-bicyclic aryl-piperazines

ABSTRACT

WHEREIN AR AND AR1, WHICH MAY BE IDENTICAL OR DIFFERENT FROM EACH OTHER, ARE EACH BICYCLIC AROMATIC FUSED-RING RADICALS, WHERE THE RING NOT DIRECTLY ATTACHED TO THE METHYLENE GROUP OR THENITROGEN ATOM OF THE PIPERAZINE NUCLEUS, RESPECTIVELY, IS AN ISOCYCLIC OR HETEROCYCLIC, SATURATED OR UNSATURATED RING, PREFERABLY 3,4-METHYLENEDIOXYPHENYL, INDANYL, TETRAHYDRONAPHTHYL, NAPHTHYL, 1,4 - BENZODIOXANYL OR CHROMANYL, AND NON-TOXIC, PHARMACOLOGICALLY ACCEPTABLE ACID ADDITION SALTS THEREOF; THE COMPOUNDS ARE WELL AS THEIR SALTS ARE USEFUL AS CENTRAL NERVOUS SYSTEM DEPRESSANTS, ADRENOLYTICS, ANTIPHLOGISTICS AND ANTI-HISTAMINES.   1-(AR-CH2-CH(-CH3)-),4-AR1-PIPERAZINE   COMPOUNDS OF THE FORMULA

Patented Apr. 30, 1974 United States Patent ()ffic US. Cl. 260-268 BC 4 Claims ABSTRACT OF THE DISCLOSURE Compounds of the formula wherein Ar and Ar which may be identical or different from each other, are each bicyclic aromatic fused-ring radicals, where the ring not directly attached to the methylene group or the nitrogen atom of the piperazine nucleus, respectively, is an isocyclic or heterocyclic, saturated or unsaturated ring, preferably 3,4-methylenedioxyphenyl, indanyl, tetrahydronaphthyl, naphthyl, 1,4 benzodioxanyl or chromanyl,

and non-toxic, pharmacologically acceptable acid addition salts thereof; the compounds as well as their salts are useful as central nervous system depressants, adrenolytics, antiphlogistics and anti-histamines.

This invention relates to novel N-(l-bicyclic aryl-propyl-2)-N'-bicyclic aryl-piperazines and non-toxic acid addition salts thereof, as well as to methods of preparing these compounds.

More particularly, the present invention relates to a novel class of piperazine derivatives of the formula wherein Ar and Ar which may be identical or difierent from each other, are each bicyclic aromatic fused-ring radicals, where the ring not directly attached to the methylene group or the nitrogen atom of the piperazine nucleus, respectively, is an isocyclic or heterocyclic, saturated or unsaturated ring, preferably 3,4-methylenedioxyphenyl, indanyl, tetrahydronaphthyl, naphthyl, 1,4-benzodiox- 'anyl or chromanyl,

CH3 (III) wherein Ar has the same meanings as in Formula I and X is chlorine, bromine, lower alkyl-sulfonyloxy or arylsulfonyloxy, in the presence of an acid-binding agent, such as sodium carbonate or potassium carbonate.

METHOD B By reacting an N-bicyclic aryl-piperazine of the Formula II above with a l-bicyclic aryl-propanone-Z of the formula wherein Ar has the same meanings as in Formula I, in the presence of catalytically activated hydrogen.

METHOD C By reacting a racemic or optically active N-(l-bicyclic aryl-propyl-2)-N'-bicyclic aryl-ethylenediamine of the formula wherein Ar and Ar have the same meanings as in Formula I, with a compound of the formula wherein X has the same meanings as in Formula III, such as a dihaloethane, and especially dibromoethane, in the presence of an acid-binding agent at elevated temperatures.

The starting compounds required for Methods A, B and C are, to a large extent, known compounds or may be prepared by known methods.

A compound of the Formula II, for instance, may be prepared by the processes described in J.A.C.S. 76, 1853 (1954) and J. Med. Chem. 8, 332 (1965).

An electrophilic l-bicyclic aryl-propyl-2 compound of the Formula III may be obtained by esterification of a corresponding l-bicyclic aryl-propanol-Z (see Examples 8 and 9 below).

A l-bicyclic aryl-propanone-Z of the Formula IV may, for instance, be prepared by the process described in Org. Synth. Coll., vol. IV, page 573, and reduction of the same with lithium aluminum hydride yields the corresponding l-bicyclic aryl-propanol-Z needed for the preparation of a compound of the Formula III.

A compound of the Formula V may, for example, be prepared by the processes described in German Auslegeschrift 1,212,973.

Finally, a compound of the Formula VI may be obtained by esterification of ethylene glycol, or by addition of halogen to ethylene, or by halogenation of ethane.

The compounds of the Formula I comprise an assymmetric carbon atom in the CH(CH grouping and, accordingly, occur in the form of racemates as well as optically active antipodes. The optically active compounds may be obtained either by using the corresponding optically active starting Compounds III, IV or V in Methods A, B or C, respectively, or by converting a racemate of a compound of the Formula 1 into a diastereosalt thereof with the aid of an optically active auxiliary acid, such as dibenzoyl-Dtartaric acid or D-3-bromocamphor-S-sulfonic acid, and separating the optically active components by fractional precipitation or fractional crystallization, pursuant to conventional procedures.

The racemates and optically active antipodes of the compound of the Formula I are organic bases and therefore form acid addition salts with inorganic or organic acids. Examples of non-toxic, pharmacologically acceptable acid addition salts are those formed with hydrochloric acid, hydrobromic acid, sulfuric acid, methanesulfonic 3 acid, succinic acid, tartaric acid, 8-chlorotheophylline or the like.

The following examples further illustrate the present invention and will enable others skilled in the art to understand it more completely. It should be understood, however, that the invention is not limited solely to the particular examples given below.

EXAMPLE 1 N- 1- (indanyl-S -propyl-2] -N- ot-naphthyl -piperazine and its monohydrochloride by Method A A mixture consisting of 84 gm. of l-(indany1-5)-propyl-2 methanesulfonate, 65 gm. of N-(a-naphthyl)-piperazine, 64 gm. of anhydrous sodium carbonate and 500 ml. of xylene was refluxed for four hours. Thereafter, the reaction mixture was vacuum-filtered to separate the insoluble inorganic salts which had formed, the filtrate was evaporated in vacuo, and the residue was admixed with methanol and aqueous hydrochloric acid. The crystalline slurry formed thereby was vacuum-filtered, and the filter cake was recrystallized from aqueous methanol, yielding the compound of the formula i CH.

having a melting point of 300-304 C.

The free base, which was obtained by treating the monohydrochloride with ammonia, had a melting point of 90-91" C.

EXAMPLE 2 N-[l-(B 5,6,7,8 tetrahydronaphthyl) propyl-2]-N- (a-naphthyl) -piperazine monohydrochloride by Method A A mixture consisting of 54 gm. of 1-(fi-5,6,7,8-tetrahydronaphthyl)-propyl-2 methanesulfonate, 38 gm. of N- (a-naphthyD-piperazine, 38 gm. of anhydrous sodium carbonate and 300 ml. of xylene was refluxed for four hours. Thereafter, the reaction mixture was vacuumfiltered to separate the insoluble inorganic salts which had formed, the filtrate was evaporated in vacuo, and the residue was admixed with methanol and aqueous hydrochloric acid. The resulting crystalline slurry was vacuumfiltered, and the filter cake was recrystallized from aqueous methanol, yielding the compound of the formula having a melting point of 306-309 C.

EXAMPLE 3 N-[ 1- (u-naphthyl) -propyl-2] -N'- (a-naphthyl) -piperazine monohydrochloride by Method A A mixture consisting of 29 gm. of l-(u-naphthyD- propyl-2 methanesulfonate, 21 gm. of N-(a-naphthyD- piperazine, 22 gm. of anhydrous sodium carbonate and 250 ml. of xylene was refluxed for four hours. Thereafter, the reaction mixture was vacuum-filtered to remove the insoluble inorganic salts which had formed, the filtrate was evaporated in vacuo, and the residue was admixed with methanol and aqueous hydrochloric acid. The resulting crystalline slurry was vacuum-filtered, and the filter cake was recrystallized from methanol, yielding the compound of the formula having a melting point of 32S327 C.

' EXAMPLE 4 N-[1-(3,4'-methylenedioxy phenyl) propyl-2]-N'-(fi- 5,6,7,8-tetrahydronaphthyl) piperazine monohydrochloride by Method A A mixture consisting of 28 gm. of N-(B-5,6,7,8-tetrahydronaphthyl)-piperazine (B.P. C. at 0.15 mm. Hg), 39 gm. of l-(3',4-methylenedioxy-phenyl)-propyl- 2 methane-sulfonate, 32 gm. of anhydrous sodium carbonate and 250 ml. of xylene was refluxed for five hours. Thereafter, the reaction mixture was vacuum-filtered, the solvent was distilled out of the filtrate in vacuo, and the residue was admixed first with methanol and then with aqueous hydrochloric acid to pH 2. The precipitate formed thereby was separated by vacuum filtration, and the filter cake was recrystallized from methanol, yielding the compound of the formula having a melting point of 25 1-25 3 C.

EXAMPLE 5 N- l- (chromanyl-6' )-propyl-2] -N'- u-naphthyl piperazine monohydrochloride by Method A A mixture consisting of 30 gm. of 1-(chromanyl-6)- propyl-2 methanesulfonate, 22 gm. of N-(a-naphthyD- piperazine, 22 gm. of anhydrous sodium carbonate and 250 ml. of xylene was refluxed for four hours. Thereafter, the reaction mixture was vacuum-filtered to remove insoluble inorganic salts which has formed, the filtrate was evaporated in vacuo, and the residue was admixed with methanol and aqueous hydrochloric acid. The resulting crystalline slurry was vacuum-filtered, and the filter cake was recrystallized from aqueous methanol, yielding the compound of the formula om-oH-N' N having a melting point of 324-3 25 C.

EXAMPLE 6 N- 1- 1,4'-benzodioxanyl-6')-propyl-2]-N'-(B-naphthyl)-piperazine monohydrochloride by Method A having a melting point of 239-241 C.

EXAMPLE 7 N-[ 1- Q-naphthyl) -propyl-2] -N'- a-naphthyl -piperazine monohydrochloride by Method A A mixture consisting of 33 gm. of l-(B-naphthyD- propyl-2 methanesulfonate, 22 gm. of N(a-naphthyl)- piperazine, 22 gm. of anhydrous sodium carbonate and 300 ml. of xylene was refluxed for four hours. Thereafter, the insoluble inorganic salts which had formed were separated by vacuum filtration, the filtrate was evaporated, and the residue was admixed with methanol and aqueous hydrochloric acid. The resulting crystalline slurry was vacuum-filtered, and the filter cake was recrystallized from methanol, yielding the monohydrochloride of N-[l-(B- naphthyl) propyl 2]-N'-(a-naphthyU-piperazine, M.P. 290-291 C.

EXAMPLE 8 N-[1-(3,4'-methylenedioxy-phenyl)-n-propyl-2]-N'-( 3- indanyl)-piperazine monohydrochloride by Method A (a) 107 gm. of 1 (3',4-methylenedioxy-phenyl)-propanone-2 were reduced in ethanol with 14.2 gm. of sodium borohydride, yielding 1-(3,4'-methylenedioxy-phenyl)-propanol-2 (B.P. l53156 C. at 14 mm. Hg), which in turn was reacted with p-toluenesulfonic acid chloride in pyridine, yielding 1 (3',4'-methylenedioxy-phenyl)- propyl-2 p-toluenesulfonate, B.P. 58 C.

(b) A mixture consisting of 35.6 grn. (0.11 mol) of l (3',4'-methylenedioxy-phenyl)propyl-2 p-tolenesulfonate, 20.1 gm. (0.1 mol) of N-(fl-indanyD-piperazine, 21.2 gm. (0.2 mol) of anhydrous sodium carbonate and 250 ml. of xylene was refluxed for five hours. Thereafter, the insoluble inorganic salts which had formed were separated by vacuum filtration, the solvent was distilled out of the filtrate in vacuo, the residue was stirred with dilute hydrochloric acid, the mixture was vacuum-filtered, and the filter cake was recrystallized from methanol, yielding the compound of the formula having a melting point of 266-268 C.

EXAMPLE 9 N-[1-(1',4'-benzodioxanyl-6')-propyl-2]-N'-(u-naphthyl)-piperazine monohydrochloride by Method A (a) 76 gm. of 1-(1',4'-benzodioxanyl-6')-propanone-2 were reduced with 7.6 gm. of sodium borohydride in ethanol to yield l-(1,4'-benzodioxanyl-6)-propanol-2 (B.P. l20-125 C. at 0.1 mm. Hg) which, in turn, was reacted with methanesulfonic acid chloride in pyridine to yield 1-(1,4'-benzodioxanyl-6')-propyl-2 methanesulfonate, M.P. 49-50 C.

(b) A mixture consisting of 60 gm. (0.22 mol) of 1(1',4-benzodioxanyl 6) propyl-2 methanesulfonate, 42.4 gm. (0.2 mol) of N-a-naphthyl)-piperazine, 42 gm. (0.42 mol) of sodium carbonate and 300 ml. of xylene was refluxed in a vessel provided with a water separator, accompanied by stirring. Thereafter, the insoluble inorganic salts which had formed were separated by vacuum filtration, the solvent was distilled out of the filtrate in vacuo, the residue was taken up in methanol, and the resulting solution was acidified with dilute hydrochloric acid. The precipitate formed thereby was collected by vacuum filtration and recrystallized from methanol, yielding the monohydrochloride of N-[1-(1,4-benzodioxanyl- 6)-propyl-2] N' (u-naphthyD-piperazine, MP. 320- 324 C.

EXAMPLE 10 N [1 (3',4' methylenedioxy phenyl) propyl 2]- 6 N (or naphthyl) piperazine monohydrochloride by Method B A mixture of 17.8 gm. (0.1 mol) of (3,4-methylenedioxy-phenyl)acetone, 21.2 gm. (0.1 mol) of N-(fl-naphthyl)-piperazine and 250 ml. of ethanol was hydrogenated at C. and 50 atmospheres gauge in the presence of Raney nickel as a catalyst until no more hydrogen was being absorbed. Thereafter, the reaction mixture was allowed to cool, the catalyst was separated by vacuum filtration, and the ethanolic filtrate was admixed with concentrated hydrochloric acid until it reacted weakly acid. The precipitate formed thereby was collected by vacuum filtration, washed with water and ethanol, and recrystallized from methanol, yielding the compound of the formula l 'HCI CH3 having a melting point of 210212 C.

EXAMPLE 11 N [1 (3',4 methylenedioxy phenyl) propyl 2]- N (0c naphthyl) piperazine monohydrochloride by Method C (a) 17.8 gm. (0.1 mol) of (3,4 methylenedioxyphenyl)-acetone and 18.6 gm. (0.1 mol) of N-(a-naphthyl)-ethylenediamine were dissolved in 200 ml. of ethanol, and the solution was hydrogenated at 70 C. and under pressure in the presence of palladized charcoal until no more hydrogen was being absorbed. Thereafter, the catalyst was separated by vacuum filtration, and the ethanol was distilled out of the filtrate. The residue was admixed with aqueous hydrochloric acid, the mixture was stirred for about 30 minutes, then vacuum-filtered, and the filter cake was thoroughly washed first with water and then with chloroform and finally recrystallized from aqueous methanol, yielding the monohydrochloride of N- (a-naphthyl) N [(3',4' methylenedioxy phenyl)- propyl2]-ethylenediamine, M.P. 220221 C.

(b) A mixture consisting of 19.2 gm. (0.05 mol) of N-(a-naphthyl) N' [(3',4' methylenedioxy-phenyl)- propyl 2] ethylenediamine monohydrochloride, 10 gm. of 1,2-dibromoethane, 20 gm. of potassium carbonate and ml. of butanol was refluxed for ten hours. Thereafter, aqueous hydrochloric acid was added to the reaction solution, the precipitate formed thereby was collected by vacuum filtration, washed thoroughly first with water and then with chloroform, and finally recrystallized from methanol, yielding the compound of the formula having a melting point of 288292 C.

The compounds according to the present invention, that is, the racemic or optically active compounds of the Formula I and their non-toxic acid addition salts, exhibit useful pharmacodynamic properties in warmblooded animals, such as mice, dogs and rabbits.

More particularly, the compounds of the instant invention exhibit central nervous system'depressing activities with very low toxicity and are therefore useful as sedatives, neuroleptics and tranquilizers.

In addition, the compounds of the present invention exhibit adrenolytic activities and therefore have utility as hypotensives and bronchospasmolytics.

Moreover, the compounds of the Formula I and their non-toxic acid addition salts exhibit antiphlogistic and antihistaminic activities.

The compounds according to the present invention are surprisingly and unexpectedly better CNS-depressants than the structurally related compounds disclosed in German Auslegeschrift 1,189,553. Particularly effective CNS- depressants are those compounds of the Formula I wherein Ar is a bicyclic fused ring system comprising a saturated oxygen-containing ring, such as 3,4-methylenedioxy-phenyl, 1,4-benzodioxanyl or chromanyl, and Ar is a bicyclic aromatic or homocyclic fused ring system, such as a-naphthyl, p-naphthyl or fi-indanyl, and their nontoxic, pha-macologically acceptable acid addition salts. Specific examples of compounds according to the present invention which exhibit particularly effective CNS depressing activities are the following:

N- 1- 3 ',4'-methylene-dioxy-phenyl -propyl-2] -N (u-n aphthyl) -piperazine,

N-[ 1, (3 ,4'-methylenedioxy-phenyl -propyl-2] N- B-naphthyl -pip erazine,

N- l- (3 ',4-methylenedioxy-phenyl -propyl-2] -N- fi-indanyl -piperazine,

N- 1-( l,4'-benzodioxanyl-6 -propyl-2] -N'- B-naph-thyl -piperazine,

N- lchromanyl-6' -propyl-2'] -N- a-naphthyl piperazine and non-toxic, pharmacologically acceptable acid addition salts of these.

For pharmaceutical purposes the compounds according to the present invention are administered to warmblooded animals perorally or parenterally as active ingredients in customary dosage unit compositions, that is, compositions in dosage unit form consisting essentially of an inert pharmaceutical carrier and one effective dosage unit of the active ingredient, such as tablets, coated pills, capsules, wafers, powders, solutions, suspensions emulsions, syrup, suppositories and the like. One effective dosage unit of the compounds according to the present invention is from 0.25 mgm./kg. to 3.4 mgm./kg. body weight, preferably from 0.41 to 1.4 mgm./kg. body weight.

The following examples illustrate a few dosage unit compositions comprising a compound of the present invention as an active ingredient and represent the best modes contemplated of putting the invention into practical use. The parts are parts by weight unless otherwise specified.

EXAMPLE 12 Tablets The tablet composition is compounded from the following ingredients:

Parts N [l-(3, -methylenedioxy-phenyl)-propyl-2]-N'- (a-naphthyD-piperazine or its hydrochloride 30 Lactose 70 Corn starch 93 Secondary calcium phosphate 47 Soluble starch 3 Magnesium stearate 3 Colloidal silicic acid 4 Total 250 8 EXAMPLE 13 Coated pills The pill core composition is compounded from the following ingredients:

Preparation.The ingredients are compounded in the same manner as for the tablet composition of the preceding example, and the composition is compressed into 250 mgm.-pill cores, which are subsequently coated with a thin shell consisting essentially of a mixture of sugar, talcum and gum arabic. Each of the resulting coated pills contains 40 mgm. of the piperazine compound and is also an oral dosage uni-t composition with efiective CNS suppressing action.

A dosage unit composition comprising a compound of the present invention as an active ingredient may, in addition also contain another active ingredient, such as a spasmolytic and/or an analgesic, as illustrated by the following examples:

EXAMPLE 14 Tablets The table composition is compounded from the following ingredients:

Parts N [1 (3',4' methylenedioxy phenyl)-propyl-2]- N'-(;3-indanyl)-piperazine or its hydrochloride 35 (-)-N-butylscopolam-monium bromide 25 Lactose 164 Corn starch 194 Colloidal silicic acid 14 Polyvinylpyrrolidone 6 Magnesium stearate 2 Soluble starch 10 Total 450 Preparation-The piperazine compound, the scopolammonium compound, the lactose, the corn starch and the polyvinylpyrrolidone are intimately admixed with each other, the mixture is moistened with an aqueous solution of the soluble starch, the moist mass is granulated through a fine-mesh screen, the granulate is dried and admixed with the magnesium stearate and the colloidal silicic acid, and the resulting composition is compressed into 450 mgm.-tablets in a conventional tablet-making machine. Each tablet contains 35 mgm. of the piperazine compound and 25 mgm. of the scopolammonium compound and is an oral dosage unit composition with effective CNS- depressing and spasmolytic actions.

EXAMPLE l5 Suppositories The suppository composition is compounded from the following ingredients:

9 Preparation.-The piperazine compound, the methampyrone and the lecithin, all in finely divided form, are homogeneously distributed in the suppository base at about 40 C. with the aid of an immersion homogenizer,

and 1832 mgm.-portions of the mixture are poured into cooled suppository molds. Each suppository contains 30 mgm. of the piperazine compound and 10 mgm. of methampyrone and is a rectal dosage unit composition with effective CNS-depressing and analgesic actions.

Analogous results were obtained when any one of the other piperazine compounds embraced by Formula I or a non-toxic acid addition salt thereof was substituted for the particular piperazine compound in Examples 12 through 15. Likewise, the amount of active ingredient in these illustrative examples may be varied to achieve the dosage unit range set forth above, and the amounts and nature of the inert pharmaceutical carrier ingredients may be varied to meet particular requirements.

While the present invention has been illustrated with the aid of certain specific embodiments thereof, it will be readily apparent to others skilled in the art that the invention is not limited to these particular embodiments, and that various changes and modifications may be made without departing from the spirit of the invention or the scope of the appended claims.

We claim:

1. A racemic or optically active compound of the formula HzC-O CHr- CH-N wherein 10 Ar; is naphthyl, tetrahydronaphthyl, or indanyL. or a non-toxic, pharmacologically acceptable acid addition salt thereof.

2. A compound according to claim 1, which is N-[l- (3',4' methlenedioxy phenyl) propyl 2] N (anaphthyl) piperazine or a non-toxic, pharmacologically acceptable acid addition salt thereof.

3. A compound according to claim 1, which is N-[l- (3',4' methylenedioxy phenyl) propyl 2] N' (B- naphthyl) piperazine or a nontoxic, pharmacologically acceptable acid additional salt thereof.

4. A compound according to claim 1, which is N-[l- (3',4' methylenedioxy phenyl) propyl 2] N' (flindanyl) piperazine or a non-toxic, pharmacologically acceptable acid addition salt thereof.

References Cited UNITED STATES PATENTS 2,909,523 10/ 1959 Bach 260-268 BQ 3,119,826 1/ 19-64 Regnier 260268 BC 3,419,560 12/1968 Bernstein 260-268 BC 3,562,277 2/1971 Hansen 260268 BC 3,729,474 4/ 1973 Mentrup 260268 BC 3,362,956 1/1968 Archer 260-268 BC 3,472,853 10/1969 Archer 260-268 BC 3,585,193 6/1971 Regnier et a1. 260268 BC 3,119,826 1/ 1964 Regnier et al. 260-268 BC FOREIGN PATENTS 1,176,672 1/ 1973 Great Britain 260-268 PH 1,190,466 4/ 1965 Germany 260268 PH DONALD G. DAUS, Primary Examiner H050 UNITED STATES PATENT OFFICE 59 CERTIFICATE OF CORRECTION 3,808,212 April 30, 1974 Patent: No. Dated I ERNST--OT'IO REN'I'H, ANTON MENI'RUP, KURT SCI-IROMM, ROLF GIESEMKNN It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 3 line 25, that portion of the formula which now reads:

u i n o should read Col. 3 line 55, that portion of the formula which now reads:

('JH2-CH-N 7 CH should read:

- CH -CH-N Signed and sealed this 29th day of October 1974.

(SEAL) Attest:

MCCOY M. GIBSON- JR. C. MARSHALL DANN Attesting Officer 7 Commissioner of Patents 

